The Cedar Rapids oncology Project CC0P has provided an active cancer research program to eastern Iowa and western Illinois since 1965. CROP is comprised in Cedar Rapids, Iowa, of Mercy Medical center, St. Luke's Hospital, the Hall Radiation Center and Oncology Associates; and in Moline, Illinois, of United Medical Center and the oncology section of Medical Arts Associates. These components are the primary providers of specialized cancer care to these communities. All medical oncologists and radiotherapists practicing in Moline and Cedar Rapids are participants with this research effort. Modern, sophisticated and comprehensive diagnostic and treatment facilities are available. The components of CROP provide cancer care to a population base of 500,000 people in eastern Iowa and western Illinois. It is estimated that CROP sees 80% of newly diagnosed cancer patients from this region for an annual total of 1,500 to 1,600 patients. Approximately 40% of patients accrued to CROP studies are from rural areas. Expertise has been gained meeting the special needs and problems of providing cancer research to this large rural population. CROP has functioned since 1985 and the continuity of this program, with experienced key personnel, has allowed for steady expansion and exceptional quality control. There have been no major violations and extremely low rates of ineligibility (1.3%) have been maintained since 1985 covering over 1,000 study entries. Internal as well as external quality assurance measures have been developed and carefully tested. Quality control is further validated by results of a recent audit conducted by its research bases. CROP identifies NCCTG as its primary research base, with EC0G and NSABP as secondary research bases. These multiple bases provide the availability of a comprehensive cancer treatment and control research program appropriate for community participants. Participation with NSABP has allowed access to the Breast Cancer Prevention Trial (BCPT). Cancer treatment and cancer control accrual has steadily increased with CC0P participation. In 1988, before CC0P funding, 75 treatment patients were entered, and this has increased in 1991 to 133 cancer treatment entries. Cancer control accrual has also increased with activation of the BCPT. After two months of participation with the BCPT, 10 patients have been randomized and 87 women have given signed consent and are in the process of being placed on study. It is expected that the CCOP will exceed 50 cancer control credits in 1992. A detailed organizational structure arid data management plan is submitted. These systems are operational and have proven effective through years of research participation. CROP has documented its ability to provide an effective multi-disciplinary cancer research program. Continuation of CROP as a funded CC0P will permit greater and more productive efforts.